Warning magnetic unit



Feb 22E9 W49. J. @Boom 2,462j15 WARNING MAGNETIC UNIT Filed sepi. le, 1944 IN VEN TOR.

Jnzes C. 8002512 ATTORNEY Patented Feb. 22, 1949 UNITED STATES PATENT OFFICE WARNING MAGNETIC UNIT James C. Booth, Jackson Heights, N. Y.

Application September 16, 1944, Serial No. 554,385

l Claim.

This invention relates to new and useful improvements in a warning magnetic unit.

More specically, the invention proposes the construction of a warning device characterized by a plug adapted to be screwed into a port opening into an engine or similar structure and having a magnet connected to a signal, whereby when the magnet draws a broken fragment of metal from the engine to it, the metal closes the circuit and actuates the signal.

Still further, it is proposed to provide a device as aforesaid having two separate magnet members, one forming the north pole and the other the south pole of the magnet, these members being connected by a magnetic conductor, which is a crystal which continues the magnetic flux.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claim in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. l is a central sectional view of a device constructed in accordance with this invention, parts being shown in full.

Fig. 2` is an enlarged perspective view of one of the magnet members of the device.

Fig. 3 -is an enlarged perspective view of the plug of the device.

Fig. 4 is an end view, taken from the left of Fig. 3, of the plug.

The warning device, constructed in accordance with this invention, comprises a tapered metal plug I having external threads and adapted to be screwed into a port opening in a part of an I engine such as an airplane engine.

The plug has two parallel orifices I I extending between an inner recess I2 and an outer recess I3. A gasket I4 is provided adjacent an external ange I5 of the plug for sealing the port that the plug is screwed in. The bottom of the recess I2 is lined with an insulating washer I6 and the bottom of the recess I3 is lined with an insulating washer I1, washers I6 and I1 having orifices in line with orifices II. Tubular insulation I8 lines one of the orifices II.

Two magnet members I9, best shown in Fig. 2, are secured to the plug, each of the magnet members having a magnetized body provided with a shoulder 2I and a threaded stem 22 welded to the body. Stems 22 extend through the orifices I I and are secured therein by nuts 23. The stems 22 are smaller than the bodies 20. the bodies 20 abutting against the washer I6 and the nuts 23 abutting against the washer I1. Thus one of the magnet members is insulated from the metal plug. The other pole is grounded. They are disposed so that the shoulders 2i face each other. The members are magnetized, one as a north pole and the other as a south pole. As each is separate, they can be magnetized very easily and economically.

A magnetic conductor'crystal 24 is jammed or soldered between the members I9 and is retained in this position by the shoulders 2I. This crystal prolongs the magnetic life of the members. It is not an electrical conductor. Nuts 25 on the ends of stems 22 secure wires 26 to the magnet members, wires 26 leading one to a terminalof a lamp 21 and the other to a terminal oi' an electric plug 28 for connection with either a battery or magneto (not shown). The other terminal of the lamp is connected to the other terminal of the plug by another wire 29 in the usual manner.v

The operation of the device is as follows:

If some part of the engine or other structure in which the device is disposed should break, as for instance if a fragment of a piston should part from the rest of the piston, the magnet members I9, one of which is a north pole and the other of which including the body of the plug is a south pole when the crystal 24 is jammed or soldered therebetween, would draw the fragment of metal to the free ends of the members I9 or between the north pole and the body of the plug. The crystal held between the two straight magnets, increases the magnetic flux or the attractive power of the magnets. The fragment would cross the members I9, thereby closing the electric circuit of the wires 2B and light the lamp. It is contemplated that in an airplane the lamp would be on the dashboard or instrument panel where the pilot could see it light and thus be warned that-a part of his engine had become broken. If desired, -a buzzer could be used instead of the lamp 21 so that a. noise would be made to attract the attention of the pilot, or a buzzer and a lamp both could be employed, thus providing both a visual and a noisemaking warning signal.

While I have illustrated and described the preferred embodiments of my invention,it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modifications comf ing within the scope of the invention as defined in the appended claim.

Having thus described my invention, what I 3 claim as new, and desire to secure by United States Letters Patent is:

A magnetic metal detecting plug, comprising an externally threaded plug body for mounting in e, threaded opening formed in a motor casing, said plug body having its ends formed with 'recesses and spaced orices extended therethrough between the base walls of said recesses, washers of insulation material disposed in said recesses and formed with orifices in alignment with said orti-lees of said plug hody, bar magnets within the recess of said plug body on the inside of the motor casing and arranged in axial alignment with said aligned orices and of a cross-sectional size slightly greater than the diameter of said aligned orifices to abut the outer face of the adjacent washer about its orices, said bar magnets having unlike poles extended away from said plug body, threaded stems continuing from said bar magnets in axial alignment therewith and extended through said aligned orifices and projected beyond the other end of said tubular body, a tubular insulator in one of said orifices of said tubular body between the nuts.

JS Cn BGOTH.

REFERENCES The following references are o record in the ille of this patent:

Number N Bete 579,496 Osborn Nov. 3, 1326 1,281,842 Resnick et al. Oct. 15, 1918 2,015,156 Richmond Sept. 24, 1935 2,076,136 Weed Apr. 6, 1937 2,203,321 Bescom June 4, 1940 2,252,222 Ven Os Aug. 12, 1941 

